London-based high-end jeweller Graff Diamonds filed a listing application for its planned initial public offering of about $1 billion in Hong Kong On Thursday, a source with direct knowledge of the IPO plans told Reuters.

The application could see the company, founded by Laurence Graff in 1960, list in the second quarter to join Prada <1913.HK> and other global brands looking to tap booming luxury demand in China. The source was not authorized to speak publicly on the IPO plans.

Graff would vie for investors' funds with more than 80 companies that had active IPO applications in Hong Kong through the end of January. Canadian oil explorer Sunshine Oilsands Ltd is set to price its IPO for up to $700 million next week, in what is expected to be another slow year after demand for new listings slumped 42 percent in 2011.

Sales at Graff, whose giant gems and rare diamonds have been used by royals and celebrities such as the sultan of Brunei, Oprah Winfrey and Imelda Marcos, are equally split between the United States, Europe and Asia. But growth in Asia is far outpacing other markets, Graff's founder told Reuters in a November interview.

The offering would help the company raise funds to boost its inventory of precious stones and better compete with publicly traded luxury goods and jewellery rivals such as Richemont , LVMH and Tiffany's , he said.

The company, which flew in three 100-carat diamonds to its flagship Hong Kong store in November to dazzle customers, plans to open two new stores in China this year. One will be in Macau's glitzy gambling enclave at Wynn Macau <1128.HK> casino and another in Hangzhou, an affluent city one hour from Shanghai by train.

Credit Suisse Group AG , Deutsche Bank AG , Goldman Sachs Group Inc and Morgan Stanley were hired as joint global coordinators on the IPO, Thomson Reuters publication IFR reported previously.

(Reporting by Elzio Barreto; Editing by Kim Coghill and Richard Pullin)